DESCRIPTION: This application seeks five years of funding to collect, analyze, and disseminate data for a fifth wave of the National Long-Term Care Survey (NLTCS) intended for 1999. The wave is planned to include 5,971 detailed non-institutionalized interviews and 1,484 detailed institutionalized interviews, along with 11,038 additional screening interviews and 707 non-interviews, amounting to 19,245 subjects in total. All subjects from previous waves identified as still living and residing in the United Sates (estimated at 3,967) will be interviewed to maintain the longitudinal sample originating in 1982 and augmented in 1984, 1989, and 1995. New sample members will be drawn from people passing the age-65 boundary between 1994 and 1999, along with people newly screened for chronic disability or newly selected to maintain representativeness of a healthy subsample. A new subsample of 600 persons over age 95 will be drawn from Medicare records. The data collection, as in previous waves, will be accomplished through a subcontract with the U.S. Census Bureau. The new NLTCS wave will maintain comparability of questions measuring chronic disability, Alzheimer's disease and related dementias and care and service utilization, so that trends in disability, active life expectancy, and mortality can be estimated by age and cohort over an 18-year-long time stretch from the start of 1982 to the end of 1999. Data from all waves will be linked to each other and to Medicare Part A and Part B service use records and mortality records from 1982 through 2000, so that longitudinal analysis of service use and cost can be conducted. Three new areas will be probed in the 1999 wave. First is the relation between nutrition, disability, and cognitive function through a short food frequency assessment. Second is the prevalence of the APO-E genetic polymorphisms recently shown to be associated with risk of Alzheimer's Disease as well as circulatory diseases; this genetic information will be collected for an age-stratified sample of 1,500 people over age 80. Third is the prevalence of polymorphisms of the WRN gene recently implicated in Werner's Syndrome and possibly affecting rates of health changes at extreme ages. The biological samples will be obtained using a non-invasive cheek swab, and the genetic typing will be accomplished through a subcontract with the University of Washington for with Dr. George Martin as Principal Investigator. Planned in-house analyses include the updating of studies of temporal trends in components of disability and dementia, of costs and service utilization, and of active life expectancy up to the year 2000. Educational effects and birth-cohort effects are to be emphasized. The stochastic risk-factor models and Grade of Membership models developed by this group at Duke will be extended and applied. A public use file containing linked data from all waves of the NLTCS along with linked Medicare service use and mortality records will be prepared and electronically disseminated. According to a letter of clarification submitted subsequent to the application by the Principal Investigator and provided to reviewers, an outside users' conference and an early results conference are contemplated (presumably through a supplementary application) to facilitate widespread use of the NLTCS data.